What is the effect of the b value in an exponential function? y-a*b^x
please help me

Answer asap evaluate 4-0.25g+0.5h4−0.25g+0.5h when g=10g=10 and h=5h=5.

Plz hurry evaluate the expression a+b where a=8 and b=19

Astudent must have an average on five test that is greater than it equal to 80% but less than 90% to receive a final grade of b. devon's greades on the first four test were 78% 62% 91% and 80% what range if grades on the fifth test would give him a b in the course? ( assuming the highest grade is 100%)